fix: run init-job on first install

[jonasbadstuebner]

There are multiple issues stating the init-job is not run as expected

This is because there is a deadlock with the CRDB-StatfulSet requiring the init-job to run, which is only ran by Helm when the StatefulSet is considered ready

The optional use of the --wait of helm install is causing differing observations

This PR attempts to fix the problem by using the Job as plain Job instead of hook when the Chart is initially installed

[jonasbadstuebner]

⚠ Not tested yet ⚠
The rendering looks good - I am just not sure if this behaves as I think it does.
If someone else wants to test it, feel free.

Expected behavior:
On install (--wait given or not does not matter):

1. The CRDB-StatefulSet and the init-Job are deployed almost at the same time
2. The init-job initializes the DB - once it is ready for initialization - and finishes
3. The `helm install` command succeeds
4. The Job is eventually auto-deleted by Kubernetes due to the `ttlSecondsAfterFinished` being 0
   (this unblocks the `helm upgrade`)

On Upgrade:

(0. The init-Job is removed, if present from a previous `helm upgrade` - should not be
    there anymore from the `helm install` step)
1. The CRDB-StatefulSet is upgraded
2. The init-Job is run after the StatefulSet is upgraded and ready
3. The `helm upgrade` command succeeds

[jonasbadstuebner]

The open issues related to the init-job deadlock:
For sure:
#69
#287
#402

Probably:
#345 (same error message)

The closed issues related to the init-job deadlock:
#195
#234
#389 (I'd argue this is the same topic, even though the person put the blame on terraform)
#400
#410

This just shows that the topic is highly confusing, as people expect a simple helm install to work. I really hope my solution works.
Otherwise, I would love to see a big note in the README at least, to not use --wait on helm install.

[jonasbadstuebner]

I just had big success with the init job.

The changes I propose in this PR seem to do their job (pun intended...?).

The cluster was initialized without any manual action.
This is my install and upgrade section for the Fluxv2 HelmRelease:

apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
[...]
spec:
  install:
    remediation:
      retries: -1
  upgrade:
    remediation:
      retries: -1

Nothing special required here, as you can see. Flux enables --wait and --wait-for-jobs per default, so these flags should work on the normal helm install command after my changes too.

The init-job was applied in parallel to the StatefulSet, ran in the loop until the CRDB-pods accepted the init-command, ran the init, printed a success message and stayed as "completed" (which is expected and totally fine) before I got the Helm install succeeded message.

And when the upgrade ran, it removed the previously installed job - because of the helm.sh/hook-delete-policy: before-hook-creation annotation - and it ran the job after the StatefulSet was fully restarted.

Side-Note: It is probably debatable, if the init-job is even needed at all on upgrade...because what does it do there?

I mark this PR as ready and would be happy to address any questions or notes regarding my code changes.

[jonasbadstuebner]

I'm unsure what a good title for this PR would be, so if you have one, let me know please

[jonasbadstuebner]

closes #69
closes #287
closes #402
closes #345 (I think - as I said, it is the same error message and the behavior is the same as when the init-job is not run because the StatefulSet did not become ready - also the person used --wait=true in their install command)